PHYSICS

Question 1

Pressure

Answer 1

Pressure = Force / Area

𝐹
ー
𝐴

Question 2

Velocity

Answer 2

Velocity = displacement / change in time

∆𝑥
ー
∆t

Question 3

Acceleration

Answer 3

Acceleration = (Final velocity - Initial velocity) / (Final time - Initial time)

∆𝑣
ー
∆t

Question 4

Density

Answer 4

density = mass / volume

𝑚
ー
𝑣

Question 5

Speed

Answer 5

average speed = distance moved / time taken

Question 6

Momentum

Answer 6

momentum = mass x velocity

Question 7

Weight

Answer 7

weight = mass x 𝑔

Question 8

Moment of a force

Answer 8

= force x perpendicular distance from point

Question 9

Stretched spring

Answer 9

stretched spring = spring constant x extension

𝐹 = 𝑘𝑥

Question 10

Force

Answer 10

Force = mass x acceleration

𝐹 = 𝑚𝑎

Question 11

Pressure in a liquid

Answer 11

pressure = density x 𝑔 x depth

𝑝=𝘱𝑔𝒽

Question 12

Work

Answer 12

= force x distance moved in direction of force

𝑊 = 𝐹𝑑

Question 13

Gravitational potential energy

Answer 13

= mass x 𝑔 x height

𝑃𝐸 = 𝑚𝑔𝒽

Question 14

Kinetic energy

Answer 14

½ x mass x velocity^2

𝐾𝐸 = ½𝑚𝑣^2

Question 15

Boyle’s law / Compressing gases

Answer 15

For a fixed mass of gas at constant temperature:

pressure₁ x volume₁ = pressure₂ x volume₂

𝑝₁𝑉₁ = 𝑝₂𝑉₂

Question 16

Charge and current

Answer 16

charge = current x time

𝑄 = 𝐼𝑡

Question 17

Resistance, voltage (PD), current

Answer 17

voltage = current x resistance

𝑉 = 𝐼𝑅

Question 18

Total resistance in series

Answer 18

𝑅 = 𝑅₁ + 𝑅₂

Question 19

Total resistance in parallel

Answer 19

1/𝑅 = 1/𝑅₁ + 1/𝑅₂

Question 20

Electrical power

Answer 20

power = voltage (PD) x current

𝑃 = 𝑉𝐼

Question 21

Waves

Answer 21

speed = frequency x wavelength

𝑣 = 𝑓λ

Question 22

Power

Answer 22

= energy transformed / time taken

OR

= work done / time taken

Question 23

100% Efficient transformer

Answer 23

power input = power output

𝑉₁𝐼₁=𝑉₂𝐼₂

Question 24

Transformers

Answer 24

output voltage / input voltage = output turns / input turns

𝑉₂ / 𝑉₁ = 𝑛₂ / 𝑛₁

Question 25

Electrical energy

Answer 25

= power x time = voltage (PD) x current x time 𝐸 = 𝑉𝐼𝑡

Question 26

Refraction of light

Answer 26

refractive index = sine of angle of incidence / sine of angle of refraction 𝑛 = sin 𝑖/ sin 𝑟

Question 27

Total internal reflection

Answer 27

sine of critical angle = 1/refractive index sin 𝑐 = 1/𝑛

Question 28

Efficiency

Answer 28

= useful work done / total energy input OR = useful energy output / total energy input OR =useful power output / total power input